Threats to Survival of the Neotropical Otter
This is mostly from Waldemarin (2004) and Gallo-Reynoso (2002).
Habitat Degradation and Destruction
Slash and burn clearing for crops and cattle rearing, and large scale logging, always to produce maximum yield in minimum time, destroys jungles, woods and riverside vegetation. Run-off from destablised soils erodes river banks and deposits silt, reducing the amount of prey species in rivers. Wetlands are used for landfill, or drained for agriculture. Mangrove and marshes are destroyed for commercial shrimp farming. All of this degrades and destroys otter habitat.
Water Pollution
Rapid population growth and urban expansion in some areas require major quantities of water for drinking and industry extracted from the rivers, which in Mexico particularly is affecting the water table and depleting water sources. The waste water from these settlements is discharged back into the rivers loaded with organic matter, contaminants and litter. Across the region, increased used of pesticides and fertilizers leads to run-off loaded with these pollutants. As industrial development increases, heavy metals are entering the water system, bioconcentrating in prey species and leading to otter deaths and reproductive failure (Maldonaldo & Gonzalez, 2003).
Traditional fishing methods over much of the range of the Neotropical River Otter use venoms extracted from toxic plants to poison fish, and incidentally fish-eaters and other water users. This has now been augmented with the use of explosives, quick lime and electrocution (with dynamos), rendering entire areas of river sterile. In many countries these methods are illegal, but there is little or no enforcement.
Habitat Fragmentation
Many areas have been declared protected, and some of these genuinely are refuges for Neotropical Otters, and there are also areas untouched as yet by habitat degradation and water pollution, but, especially in arid areas, and areas of low population numbers, these are effectively islands of animals, with limited genetic diversity, otter flow in or out, and little room for expansion as young animals disperse to find territories of their own. There will be a tendency for genetic drift in these isolated areas, and the fixing of characteristics, and they will also be very vulnerable to being wiped out by changes in climate, water quality and habitat change.
Hunting as Resource Competitor
Where fish or shrimp farming is done, otters will raid ponds and may be shot as competitors.
Hunting for Fur
There is little traditional use of otters as food in their range, but some indigenous use of skins for clothing in the poorest areas. In coastal areas of Mexico, some people take cubs as pets. Otter fur has been found in tourist stores as wallets, jackets and bags, even though the species has been formally protected since 1973. In some areas, widespread illegal hunting for skins for export still takes place but the scale is, of course, unknown.
Neotropical River Otter |